EP0134065A1 - Composition vitrifiable contenant des fluorures de métaux - Google Patents

Composition vitrifiable contenant des fluorures de métaux Download PDF

Info

Publication number
EP0134065A1
EP0134065A1 EP84302617A EP84302617A EP0134065A1 EP 0134065 A1 EP0134065 A1 EP 0134065A1 EP 84302617 A EP84302617 A EP 84302617A EP 84302617 A EP84302617 A EP 84302617A EP 0134065 A1 EP0134065 A1 EP 0134065A1
Authority
EP
European Patent Office
Prior art keywords
glass
cdf
pbf
composition
lif
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP84302617A
Other languages
German (de)
English (en)
Other versions
EP0134065B1 (fr
Inventor
Paul Arthur Tick
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Corning Glass Works
Original Assignee
Corning Glass Works
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Corning Glass Works filed Critical Corning Glass Works
Priority to AT84302617T priority Critical patent/ATE30309T1/de
Publication of EP0134065A1 publication Critical patent/EP0134065A1/fr
Application granted granted Critical
Publication of EP0134065B1 publication Critical patent/EP0134065B1/fr
Expired legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C3/00—Glass compositions
    • C03C3/32—Non-oxide glass compositions, e.g. binary or ternary halides, sulfides or nitrides of germanium, selenium or tellurium
    • C03C3/325—Fluoride glasses
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S501/00—Compositions: ceramic
    • Y10S501/90—Optical glass, e.g. silent on refractive index and/or ABBE number
    • Y10S501/904—Infrared transmitting or absorbing
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S65/00—Glass manufacturing
    • Y10S65/15—Nonoxygen containing chalogenides
    • Y10S65/16—Optical filament or fiber treatment with fluorine or incorporating fluorine in final product

Definitions

  • the invention is in the field of glass manufacture, and particularly relates to the manufacture of non- oxide glasses of a type described as halide glasses. Specifically, the invention relates to novel metal fluoride glass compositions which are of interest for glass products such as infrared-transparent optical devices, e.g. glass optical waveguides.
  • compositions based on BeF 2 are the compositions based on BeF 2 .
  • these compositions share the shortcomings of most other halide glasses in that they exhibit relatively short working ranges and are prone to devitrification.
  • BeF 2 is both hygroscopic and highly toxic.
  • U.S. Patent No. 4,141,741 discloses a family of zrF 4 -based glass-forming compositions in the ZrF4-BaF2-ThF4 composition system which exhibit infrared transparency to about 7 microns and which are non-hygroscopic.
  • U.S. Patent No. 4,308,066 discloses a family of fluoride compositions based on ZrF 4 and/or AlF 3 , containing 20-80 mole percent of CaF 2 , SrF 2 , BaF 2 and/or PbF 2 , which will form glasses if rapidly quenched.
  • ThF 4 -ZrF 4 compositions containing fluorides selected from LaF 3 , YF 3 , CdF 3 , LuF 3 and ScF 3 as glass modifiers. These compositions provide relatively stable glasses, inhibiting glass transition temperatures in the 460-515°C range, which can be formed by casting and are infrared-transparent to about 7 microns.
  • Glasses based on fluorides other than zrF 4 are also known.
  • S. Shibata et al. disclose, in Mat. Res. Bull., 15, 129-137 (1980), a family of PbF 2 -based glasses in the PbF 2 -AlF 3 system which will form glasses if rapidly quenched.
  • M. Matecki et al., Mat. Res. Bull., 17, 1275-1281 (1982) report glasses based on CdF 2 , including binary CdF 2 -BaF 2 and ternary CdF2-BaF2-ZnF2 compositions optionally containing AlF 3 , YbF 3 , ThF 4 and/or alkali metal fluorides. These compositions will also form thin, infrared transmitting glass elements if rapidly quenched.
  • the present invention provides novel fluoride glass compositions in the CdF 2 -AlF 3 -PbF 2 composition system, desirably containing LiF, which form stable glasses without rapid quenching.
  • the glasses exhibit the infrared transparency characteristic of halide glasses, and in addition are potentially manufacturable by chemical vapor deposition techniques.
  • the present invention provides a glass-forming composition in the CdF 2 -AlF 3 -PbF 2 ternary which comprises, in mole percent, 20-46% CdF 2 , 22-52% AlF 3 and 18-44% PbF 2 and the sum total of the mole percent of CdF 2 , AlF 3 and PbF 3 being at least 80 mole percent of the glass-forming composition, and wherein the molar ratio of CdF 2 :PbF 2 in the composition is greater than 1:2.
  • a desirable optional constituent of the glass is LiF, which may be present in an amount up to about 20 mole percent, and which has a stabilizing effect on the glass when present in the 5-15 mole percent range.
  • Other additives which may optionally be present are YbF 3 , CaF 2r , SrF 2 , BaF 2 , NaF and KF, in amounts totalling up to 10 mole percent, and ZnF in a amount up to 5 mole percent.
  • a very desirable characteristic of a candidate glass would be a composition compatible with a chemical vapor deposition process.
  • the most stable of the known heavy metal fluoride glasses rely heavily on Zr or Hf as the glass formers and Ba as a modifier. While Zr and Hf are in principle vapor transportable, most compounds of these metals have low vapor pressure, thus limiting their attractiveness as-a major glass component. Further, no high vapor pressure compound of Ba has yet been developed.
  • the components which comprise the compositions of the present invention are at least potentially vapor transportable.
  • the main metallic components Pb, Al, Cd and Li are believed to be transportable as organometallic compounds and, of the additional components that might be added to the system, Yb may also be vapor transportable.
  • FIGURE 1 is a ternary diagram plotting representative compositions in that base system.
  • the quality of glass articles made from each of the compositions shown is reflected in the circles representing the compositions;unshaded circles represent essentially crystal-free patties when formed by casting to a thickness of several millimeters on stainless steel plates, while quarter-shaded circles represent patties showing some crystallization or phase separation and half-shaded circles represent patties with significant areas of both glassy and non-glass areas, when cast under the same forming conditions.
  • the latter compositions will readily form all-glass samples if rapidly quenched.
  • a desirable optional constituent of the glasses of the invention is LiF, which appears to stabilize the composition and to increase the composition region over which crystal free glasses can easily be formed by convention casting techniques.
  • LiF can be present in the composition in amounts up to 20 mole percent, but compositions wherein the LiF content is 5-15 mole percent are preferred.
  • FIGURE 2 illustrates representative glass-forming compositions in the cdF 2 -AIF 3 -PbF 2 -LiF composition system at an LiF concentration of 10 mole percent.
  • the ternary diagram shows the levels of CdF 2 , AlF3, and PbF 2 in those compositions over the ranges 0-90 mole percent.
  • the preferred glass-forming compositions are those wherein the LiF content is 5-15 mole percent, the CdF 2 content is 21-38 mole percent, the AlF 3 content is 23-42 mole percent, and the PbF 2 content is 18-37 mole percent.
  • Optional constituents consisting of other fluorides as hereinabove set forth may be present, but the most stable glasses from the standpoint of stability are those consisting essentially of LiF, CdF 2 , AlF 3 and PbF 2 .
  • FIGURE 3 schematically illustrates, by means of the clear and partially shaded circles indicative of glass appearance, the quality of cast glass samples containing optional added metal fluorides in partial replacement for the base glass constituents LiF, CdF 2 , AlF 3 and PbF 2 .
  • the base glass to which the optional constituents were added illustrated by the central rectangle in the figure containing a clear circle representing a crystal-free glass casting, consisted of 10 mole percent LiF, 27 mole percent CdF 2 , 31.5 mole percent AlF and 31.5 mole percent PbF 2 .
  • the glass samples represented by the surrounding circles had compositions corresponding to that of the base glass, except that the indicated optional constituent replaced the indicated base glass constituent by substitution therefor in the concentration shown on the interconnecting line.
  • glass compositions which may be provided in accordance with the invention are reported in Table I below. Included in the Table are batch weights, in grams, for the fluoride constituents used to compound the glass batches, and the compositions of the resulting glasses, in mole percent. Also included for each of the compositions is a glass quality evaluation for a glass patty formed by casting the composition after melting onto steel plate. The quality indicators are as follows: 1-essentially all glass with no evidence of phase separation or devitrification; 2-mostly glass but with some observable phase separation or devitrification; 3-substantial regions of both glassy and non-glass areas.
  • Glass preparation for glasses such as reported in Table I is suitably carried out in an atmospherically controlled melting facility, essentially consisting of a double dry box, one half of which is used to prepare batch, while the other half is used for melting.
  • the glass samples may be melted under nitrogen, which is desirably maintained at less than 10 ppm O 2 and less than 1 ppm H 2 O.
  • Hygroscopic or air reactive fluorides such as AlF 3 or CdF2 can be placed in the dry box unopened, then never removed. More stable fluorides can be exposed to atmosphere before use.
  • the glass batches were prepared in the dry box, hand tumbled, placed in 30 ml platinum crucibles, then plunged into a vertical tube furnace idling at 1100°C. Ten minutes was sufficient to obtain a clear, bubble free melt. The molten glass was then cast onto a stainless steel plate and cooled, after which it was removed for characterization.
  • the stability of glasses such as shown in Table I can be more accurately characterized by use of a differential scanning calorimeter (DSC). Small chips of representative glasses are ground in a mortar and pestle and placed in the calorimeter where the glass is then heated at a heating rate of 20°C/minute. The calorimeter also contains a sample of alumina as a reference.
  • DSC differential scanning calorimeter
  • a DSC' curve typical of the more stable glasses of the invention, generated during the heating of a glass consisting of 22.5% CdF 2 , 31.5% AlF 3 , 36% PbF 2 and 10% LiF is shown in FIGURE 4 of the drawing.
  • the glass transition temperature, Tg is obtained from the first endothermic inflection, while the crystallization temperature T xtal is at the first sharp exothermic peak in the curve. The greater the difference between Tg and T xtal the more stable the glass tends to be.
  • glasses can be made even when the difference T xtal Tg is quite small, but a difference on the order of 75°C indicates sufficient stability for forming techniques such as casting. Glass transition temperatures of 270-300°C are typical of glasses of the invention, and T xtal ' - Tg values in the range of 40-120°C have been measured on these glasses.
  • Refractive index values for these glasses can be determined using the Becke-line technique and, as 0 measured at the sodium D wavelength (5493 A), is typically in the range of about 1.61-1.65.
  • the invention provides a novel family of CdF 2 -A1F 3 -PbF 2 glasses, including particularly stable LiF-CdF 2 -AlF 3 -PbF 2 glasses, which are at least potentially vapor transportable and offer good infrared transparency.
  • the high stability of these glasses and their potential availability in pure, vapor-deposited form make them promising candidates for use in the fabrication of ultra-low-loss glass optical waveguides and other infrared-transmitting optical devices.
EP84302617A 1983-08-31 1984-04-17 Composition vitrifiable contenant des fluorures de métaux Expired EP0134065B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT84302617T ATE30309T1 (de) 1983-08-31 1984-04-17 Glasbildende zusammensetzung die metallfluoride enthaelt.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US528256 1983-08-31
US06/528,256 US4537864A (en) 1983-08-31 1983-08-31 Metal fluoride glasses in the CdF2 -PbF2 -AlF3 -(LiF) system

Publications (2)

Publication Number Publication Date
EP0134065A1 true EP0134065A1 (fr) 1985-03-13
EP0134065B1 EP0134065B1 (fr) 1987-10-21

Family

ID=24104910

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84302617A Expired EP0134065B1 (fr) 1983-08-31 1984-04-17 Composition vitrifiable contenant des fluorures de métaux

Country Status (6)

Country Link
US (1) US4537864A (fr)
EP (1) EP0134065B1 (fr)
JP (1) JPS6054940A (fr)
AT (1) ATE30309T1 (fr)
CA (1) CA1209163A (fr)
DE (1) DE3466867D1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11813780B2 (en) 2018-02-27 2023-11-14 Lego A/S Polymer mold insert for an injection molding tool

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4604118A (en) * 1985-08-13 1986-08-05 Corning Glass Works Method for synthesizing MgO--Al2 O3 --SiO2 glasses and ceramics
US4680044A (en) * 1985-11-25 1987-07-14 Hughes Aircraft Company Method of modifying the refractive index of fluoride glass
US4874222A (en) * 1986-03-31 1989-10-17 Spectran Corporation Hermetic coatings for non-silica based optical fibers
US4752593A (en) * 1987-06-10 1988-06-21 Corning Glass Works Stabilized CdF2 -PbF2 -AlF3 -alkali fluoride glasses
US4883339A (en) * 1987-07-17 1989-11-28 Spectran Corporation Oxide coatings for fluoride glass
US5055120A (en) * 1987-12-15 1991-10-08 Infrared Fiber Systems, Inc. Fluoride glass fibers with reduced defects
US4898603A (en) * 1988-07-25 1990-02-06 The United States Of America As Represented By The Secretary Of The Air Force Method for manufacturing halide glass optical fiber
US4938562A (en) * 1989-07-14 1990-07-03 Spectran Corporation Oxide coatings for fluoride glass
US5108477A (en) * 1990-05-21 1992-04-28 Corning Incorporated Method for making a glass article
US5278107A (en) * 1991-11-27 1994-01-11 Corning Incorporated Optical parts and equipment using infrared athermal glasses
FR2688778B1 (fr) * 1992-03-20 1994-11-10 Verre Fluore Sa Verres fluores.
JP3411067B2 (ja) * 1993-08-27 2003-05-26 株式会社住田光学ガラス 波長上方変換透明化ガラスセラミックスおよびその製造方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2466509A (en) * 1946-08-09 1949-04-05 Eastman Kodak Co Fluoride glass
FR2521546A1 (fr) * 1982-02-18 1983-08-19 Centre Nat Rech Scient Nouveaux verres halogenes, leur preparation et leur application

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2156304C2 (de) * 1971-11-12 1973-12-13 Jenaer Glaswerk Schott & Gen., 6500 Mainz Glasiges oder kristallines Material fur phototrope dünne Schichten
DE2726170A1 (de) * 1976-06-15 1977-12-29 Anvar Fluor-glas auf der basis eines glasartigen ternaeren systems von metall-fluoriden und verfahren zu dessen herstellung
US4244722A (en) * 1977-12-09 1981-01-13 Noboru Tsuya Method for manufacturing thin and flexible ribbon of dielectric material having high dielectric constant
FR2445820A1 (fr) * 1978-07-19 1980-08-01 Marcoussis Laboratoires Verre a effet laser
FR2452469A1 (fr) * 1979-03-28 1980-10-24 Anvar Nouveaux verres fluores, leur preparation et leur application
US4308066A (en) * 1979-10-30 1981-12-29 Nippon Telegraph & Telephone Public Corporation Glass for optical fibers
FR2478618A1 (fr) * 1980-03-18 1981-09-25 Verre Fluore Sa Nouveaux verres fluores
JPS5751146A (en) * 1980-09-09 1982-03-25 Nippon Telegr & Teleph Corp <Ntt> Preparation of raw material for fluoride optical fiber
JPS57166328A (en) * 1981-04-06 1982-10-13 Nippon Telegr & Teleph Corp <Ntt> Manufacturing of preform for fluoride optical fiber
JPS57191240A (en) * 1981-05-22 1982-11-25 Nippon Telegr & Teleph Corp <Ntt> Manufacturing of optical fiber preform for infrared ray transmission
US4378987A (en) * 1981-10-15 1983-04-05 Corning Glass Works Low temperature method for making optical fibers

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2466509A (en) * 1946-08-09 1949-04-05 Eastman Kodak Co Fluoride glass
FR2521546A1 (fr) * 1982-02-18 1983-08-19 Centre Nat Rech Scient Nouveaux verres halogenes, leur preparation et leur application

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
CHEMICAL ABSTRACTS, vol. 97, no. 6, 9th August 1982, page 240, no. 42796x, Columbus, Ohio, USA; T. MANABE: "Fluoride glasses for infrared optical fibers" & SERAMIKKUSU 1982, 17(4), 271-277 *
GLASS TECHNOLOGY, vol. 20, no. 1, February 1979, pages 36-40; K.H. SUN: "Fluoride glasses" *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11813780B2 (en) 2018-02-27 2023-11-14 Lego A/S Polymer mold insert for an injection molding tool

Also Published As

Publication number Publication date
JPS6054940A (ja) 1985-03-29
JPS6363500B2 (fr) 1988-12-07
CA1209163A (fr) 1986-08-05
US4537864A (en) 1985-08-27
EP0134065B1 (fr) 1987-10-21
ATE30309T1 (de) 1987-11-15
DE3466867D1 (en) 1987-11-26

Similar Documents

Publication Publication Date Title
EP0134065B1 (fr) Composition vitrifiable contenant des fluorures de métaux
US4314031A (en) Tin-phosphorus oxyfluoride glasses
US4141741A (en) Compositions of fluoride glasses and process for manufacturing fluoride glasses
JP3154575B2 (ja) 弗燐酸塩光学ガラス
JP4362369B2 (ja) モールド成形用光学ガラス
EP0234581B1 (fr) Verre fluoré et son utilisation
EP0312084B1 (fr) Verre halogéné
AU637760B2 (en) Low liquidus, stable heavy metal fluoride glass compositions
Iqbal et al. Synthesis, characterization, and potential application of highly chemically durable glasses based on AlF3
US5360637A (en) Vapor-phase deposition of fluorine glass
JP3194804B2 (ja) 弗燐酸塩光学ガラス用調合組成物
JPH0428655B2 (fr)
US4752593A (en) Stabilized CdF2 -PbF2 -AlF3 -alkali fluoride glasses
JP2585715B2 (ja) 赤外線透過ガラス
Wang Formation of fluoride glasses based on AlF3YbF3PbF2ZnF2BaF2
JPH0558672A (ja) 新しいＡｌＦ３ 系フツ化物ガラス
JPH05279077A (ja) 弗化物ガラス
JPH05124834A (ja) 弗化物ガラス
JP2860132B2 (ja) フッ化物ガラス
Vogel et al. Thermoanalytical study of some fluoroberyllate glasses
Kumar Synthesis and properties of multicomponent fluoride glasses containing phosphorus and arsenic
Khalilev et al. Fluoroaluminate glass containing Cd, Zn, and La fluorides
JPH0421542A (ja) フッ化物ガラス組成物
JPH06122532A (ja) フッ化物ガラスファイバー
JPH0340935A (ja) フッ化物ガラス組成物

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): AT BE CH DE FR GB IT LI NL SE

17P Request for examination filed

Effective date: 19850806

17Q First examination report despatched

Effective date: 19860424

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE FR GB IT LI NL SE

REF Corresponds to:

Ref document number: 30309

Country of ref document: AT

Date of ref document: 19871115

Kind code of ref document: T

ITF It: translation for a ep patent filed

Owner name: ING. A. GIAMBROCONO & C. S.R.L.

REF Corresponds to:

Ref document number: 3466867

Country of ref document: DE

Date of ref document: 19871126

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 19930318

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19930319

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 19930322

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19930412

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19930428

Year of fee payment: 10

ITTA It: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19930430

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 19930510

Year of fee payment: 10

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 19930611

Year of fee payment: 10

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19940417

Ref country code: AT

Effective date: 19940417

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19940418

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Effective date: 19940430

Ref country code: CH

Effective date: 19940430

Ref country code: BE

Effective date: 19940430

BERE Be: lapsed

Owner name: CORNING GLASS WORKS

Effective date: 19940430

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19941101

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 19940417

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19941229

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19950103

EUG Se: european patent has lapsed

Ref document number: 84302617.0

Effective date: 19941110

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST